Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
1998-11-19
2001-09-11
Renner, Craig A. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
C360S244900, C360S245000, C360S245300
Reexamination Certificate
active
06288877
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to disk drives and more particularly to disk drive suspensions. In a particular aspect, the invention relates to novel mounting of flexible electrical conductors on suspensions using the flexure and load beam as cooperating clamp members to mechanically support the flexible conductor so as to retain the flexible conductor in place without the use of glues or other bonding expedients.
2. Background Art
The positioning of conductor wires, and of flexible conductors, laminates of conductive layers and plastic film, has been accomplished typically by adhering the conductor in place. This requires precision placement of the flexible conductor in manufacturing to register with the application of the adhesive, is time-consuming and source of defects.
It is known to use twisted wire pairs for electrical connection to the slider in a suspension. In this arrangement very thin copper wires with gold plating are ultrasonically bonded to gold plated pads on the slider to connect the slider to the pre-amp so that the head an perform reading and writing from and to the disk.
The continual diminution in size of sliders increases the effect of unwanted forces and moments from the wires modulating the flying attitude of the slider. Changes in wire length may change wire stiffness. Changes in wire orientation may change the moment on the slider exerted by the wire. Either change will affect flying height, and in the case of large moments and biases, there can be adverse effects on the reliability of the head and recording media.
In place of wires certain supported flexible conductors have been employed; these include a laminate of conductive layers, plastic film and a support backing such as stainless steel. These structures offer the advantage of combining the flexure with the electrical circuit structure. The supported flexible conductors are welded to the load beam and offer both a gimbaling function and conduction of electromagnetic signals. In addition the supported flexible conductors afford electrical connection pads at various desired locations for electrical connection with the slider pads.
For very small sliders, e.g. the 30% or pico-sized slider, the bias of the twisted wire pairs is excessive. Thinner wires also are readily broken and difficult to position for automated manufacturing. The supported flexible conductor while not prone to the problems of twisted wires is problematic because it is easily damaged during device assembly by contact with tooling used to assemble the suspensions each including the load beam, the supported flexible conductor and slider into head gimbal assemblies (HGA's). The HGA is attached to the E-block, e.g. by swaging, To keep the several sliders apart wedge-shaped comb structures are inserted between the HGA's. These wedges may damage the supported flexible conductors in place on the load beams. Cleaning of the HGA may also result in damaging contact with the supported flexible conductors, and generate contamination. Also, HGA merging into the disk packs requires use of the wedge-shaped combs affording a further opportunity for physical damage to the supported physical conductors.
SUMMARY OF THE INVENTION
The use of unsupported flexible conductors avoids many of these problems and is frequently the conductor of choice. The process of bonding these flexible conductors in place on the load beam, as by gluing, requires the use of organic glues with their attendant off-gasses, and precise positioning of both glue and conductor. Neither requirement is desirable in a manufacturing process. Further the flexible conductor is desirably shielded from damage from the comb wedges. Also, flatness of the flexible conductor must be ensured to avoid introducing a new source of bias on the head.
It is an object, therefore, of the present invention to provide a glue-less mode of support for flexible conductor on a load beam. It is a further object to provide a method of supporting a flexible conductor on a load beam in which the flexible conductor is protected from damage from comb wedges during assembly operations. It is a further object to provide a mechanical support for the flexible conductor defined by already present components of the suspension. In particular it is an object of the invention to provide opposing first and second clamp members defined by the flexure and the load beam respectively arranged to mechanically support the flexible conductor in position by simply wedging the conductor between the flexure, which is welded onto the load beam in a manner allowing a gap between the flexure body, and the opposing load beam other than at the point of their weld attachment. It is a further object to afford mechanical protection for the flexible conductor in place from combs and other intrusive mechanisms by recessing or covering the flexible conductor in its locus between the flexure and the load beam.
These and other objects of the invention to become apparent hereinafter are realized in a disk drive suspension comprising a load beam having a portion defining a first clamp member, a flexure fixed to the load beam, the flexure having a load beam-overlying portion defining a second clamp member adapted to cooperate with the first clamp member in clamping relation, and a flexible conductor comprising a laminate of conductive leads and insulating plastic film, the flexible conductor being disposed on the load beam portion and clamped there by the cooperating first and second clamp members.
In this and like embodiments, typically, solely the first and second clamp members support the flexible conductor in its disposition on the load beam portion; the load beam portion is a beam portion, the load beam further having a base portion and a spring portion arranged to support the beam portion, the beam portion having a surface opposite the flexure portion, the flexure having a plurality of circumferentially located tabs arranged to support the flexure on the load beam portion surface in spaced relation; the load beam portion is a beam portion, the load beam further having a base portion and a spring portion arranged to support the beam portion, the beam portion having a surface opposite the flexure portion, the beam portion surface being locally relieved in flexible conductor receiving relation; the reception of the flexible conductor by the relieved beam portion surface reduces the portion of the flexible conductor projecting beyond the beam portion surface; the load beam portion is a beam portion, the load beam further having a base portion and a spring portion arranged to support the beam portion, the beam portion having a surface opposite the flexure load beam-overlying portion, the beam portion surface defining a boss extending from the beam portion surface toward the flexure portion a predetermined height, the flexible conductor disposed on the beam portion having a height less than the boss predetermined height, the flexure load beam-overlying portion being secured to the load beam at the boss in flexible conductor clamping relation in cooperation with the load beam portion first clamp member; the flexure is welded to the load beam; and/or the suspension is free of bonding attachment between the flexible conductor and the flexure or the load beam at the flexure load beam-overlying portion.
In a further embodiment, the invention provides a disk drive suspension comprising a spring metal load beam, a spring metal flexure having a tongue, a frame about the tongue and a frame extension, the flexure frame extension being fixed to the load beam, the flexure frame extension having a load beam-overlying portion, and a flexible conductor comprising a laminate of conductive leads and insulating plastic film, the flexible conductor being disposed on the load beam, the flexure frame extension load beam-overlying portion and the load beam cooperating to retained the flexible conductor in its the disposition.
In this and like embodiments, typically, the flexible conductor has a given height, the load
Coon Warren
Khan Amanullah
Bachand Louis J.
Castro Angel
Magnecomp Corp.
Renner Craig A.
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